Any opinions on Spray Foam for flat roof
Never posted here before, but read a lot. Thanks for all the info over the years. I am looking at remodeling a small store. It has a nearly flat roof, maybe 1/12 pitch. It is covered with rolled asphalt, but is leaking badly. I was considering stripping asphalt, fixing any deteriorated sheathing, and having my foam guy spray with high density roofing foam and UV protective coating. Does foam work in this kind of application? Should I run a layer of ice and water guard on the sheathing before foam? All roof penetrations will be on an addition roof. This roof will have no penetrations. Roof is approx. 1800 sf with small parapet, front and sides. Any input will be appreciated.
Replies
With over 35 years experience I will tell you emphatically, don't foam your roof. You're tearing off anyway, install minimum 2" ISO board followed by either a two ply modified asphalt or a one ply EPDM or TPO roof.
Foam may work for a while, but it's big trouble down the road.
John Svenson, builder, remodeler, NE Ohio
I'll vote with the rest, but give you a link to a system we just recieved a quote on for one of our facilities out in the state.
http://www.spray-tec.com/
At nearly $5/sf with needed deck repairs (steel) the stuff is not cheap.
No personel experience with it. After reading the proposal my butt tigthened up. Spray formed cants, curbs and flashing with no metal at all? I dunno, sounds like one of those "to good to be true" products to me.
Spray foam is a dead end system.Once it is applied, when problems develop (sooner or later they will) they are incredibly difficult to trace leaks and repair them. When you give up on repairs, there is no choice but to tear off the roof to reroof. Overlay is out of the question.If the roof can't be torn off and reroofed in one day, night seals on the foam are very problematic, leaving the building and it's contents vulnerable to leaks should there be a storm during the reroof project.And is it just me, or does every big flat roof tear-off have to include a major storm during the project?John Svenson, builder, remodeler, NE Ohio
And is it just me, or does every big flat roof tear-off have to include a major storm during the project?
Not all. I have done a few with just some showers and light rains.
I'm not advocating the foam roofs. The company (utility) that I work is looking at a prposal for the fix of one of our facilities out in the state. I just happened to see it (probably wasn't suppose to).
I'm way down the food chain in this organization. My opinion or advice is seldon sought untill there is a failure of "the plan". Then I get ask "how are you going to fix it ?"
My usual (bad people skills) responce is "low yield nuclear device or C4, your call".
Edited 8/22/2009 2:00 pm ET by DaveRicheson
why a low yield????
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
I try'n to cut back.
Ya know, global warmin and thinkin green.
Gotta save the resources for the future
got it...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
don't foam...
in very short time you will have problems from leaks and drterions...
birds like to dig out chunks and haul them off...
use foam board over the sheathing and hot roof on top of that...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
<you will have problems from leaks and drterions...>
What the hell are "derterions?"
Is that from that Transformers movie?
Forrest
DIIK....
just something off the keyboard of a can't type - type...
any letter will do sortta thing.....
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"Some days it's just not worth chewing through the restraints"
Dirterians are those human creatures that are about 5-12 yers old, generally male, during their formative years while they are "in touch" with Mother Earth, before female humans gain their interest and woo them away from Mama to try and clean them up
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I have one of those!
Make that three votes against foam. Add poly-iso and use a membrane.
http://www.quittintime.com/ View Image
I lost count, but make this the fourth or fifth experienced vote against foam roofing
Welcome to the
Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
I spray closed cell all of the time.. .make it 6 votes.. .do not spray foam on the roof!
1800sf ain't that big in the flat roof world...
simple to add more pitch with tapered foamboard... I have yet to use it but seeing alot of cold applied roofing.. a few here have done them... I usually stick to torch down just because i have a dragon wagon and can apply two squares an hour and that includes doing some detail work and flashing... (once i have the roof ready to roof...)
just my 2 cents
p